On 2015-02-18 21:40, Paul Gevers wrote: > I am wondering about the following, what is the practical difference in > a shell script between > [ "$foo" ] and [ -n "$foo" ]
POSIX [1] mandates it: | -n string | True if the length of string is non-zero; otherwise, false. | string | True if the string string is not the null string; otherwise, | false. The bash builtin test / [ ] complies with that: | string | -n string | True if the length of string is non-zero. As does [ ] from test(1): | -n STRING | the length of STRING is nonzero | | STRING equivalent to -n STRING > or > [ ! "$foo" ] and [ -z "$foo" ] These follow from above. Regards, Christian [1] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/test.html -- To UNSUBSCRIBE, email to debian-mentors-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/54e63ec5.3060...@kvr.at
